Conduct preclinical studies on the physiologic disposition and metabolic transformations of antitumor agents in four animal species. Develop analytical methods of sufficient sensitivity to permit quantitative determinations of drug levels in vivo. Investigate the structure of drug metabolites discovered during the physiologic disposition studies. When appropriate, develop models applicable to selected chemotherapeutic agents and prepare computer programs for pharmacokinetic analysis of blood concentration curves and excretion data. Investigate methods to modify pharmacologic behavior in vivo and undertake limited comparative studies of the biochemical properties of congeners of drugs under investigation. Participate in collaborative clinical pharmacologic projects pertinent to the drugs under study.